DomainKeys Identified Mail, or DKIM, is a system for checking the authenticity of an email message using an electronic signature. When DKIM is enabled for a given domain, a public key is published to the global Domain Name System and a private one is kept on the mail server. If a new email is sent, a signature is issued using the private key and when the message is received, the signature is ‘scanned’ by the incoming mail server using the public key. Thus, the receiver can easily know if the email message is genuine or if the sender’s email address has been spoofed. A discrepancy will occur if the content of the email message has been modified in the meantime as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the received messages are identical and that nothing has been added or erased. This email authentication system will enhance your email security, since you can validate the authenticity of the important email messages that you receive and your partners can do the exact same thing with the messages that you send them. Depending on the particular email provider’s adopted policies, an email message that fails to pass the check may be erased or may be delivered to the receiver’s mailbox with a warning flag.